U.S. patent application number 13/650487 was filed with the patent office on 2014-04-17 for radiation signal measurement system for millimeter wave transceivers.
This patent application is currently assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION. The applicant listed for this patent is INTERNATIONAL BUSINESS MACHINES CORPORATION. Invention is credited to RANDALL M. BURNETT, II, HANYI DING, KAI D. FENG, DONALD J. PAPAE, FRANCIS F. SZENHER.
Application Number | 20140104092 13/650487 |
Document ID | / |
Family ID | 50474866 |
Filed Date | 2014-04-17 |
United States Patent
Application |
20140104092 |
Kind Code |
A1 |
BURNETT, II; RANDALL M. ; et
al. |
April 17, 2014 |
RADIATION SIGNAL MEASUREMENT SYSTEM FOR MILLIMETER WAVE
TRANSCEIVERS
Abstract
A radiation signal measurement system for millimeter wave
transceivers is disclosed. Embodiments of the present invention
utilize a laser to align the laser with an antenna. The transceiver
is then moved into the path of the laser to align the laser with
the transceiver. The transceiver or antenna orientation is changed
such that the transceiver and antenna face each other, in an
aligned position. Millimeter wave absorber material is applied to
the inside and outside of the testing chamber to minimize
reflections and interference from outside sources.
Inventors: |
BURNETT, II; RANDALL M.;
(FISHKILL, NY) ; DING; HANYI; (COLCHESTER, VT)
; FENG; KAI D.; (HOPEWELL JUNCTION, NY) ; PAPAE;
DONALD J.; (HOPEWELL JUNCTION, NY) ; SZENHER; FRANCIS
F.; (FIHSKILL, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
Armonk |
NY |
US |
|
|
Assignee: |
INTERNATIONAL BUSINESS MACHINES
CORPORATION
ARMONK
NY
|
Family ID: |
50474866 |
Appl. No.: |
13/650487 |
Filed: |
October 12, 2012 |
Current U.S.
Class: |
342/1 |
Current CPC
Class: |
G01S 2007/4086 20130101;
G01R 29/0821 20130101; G01S 3/023 20130101 |
Class at
Publication: |
342/1 |
International
Class: |
H01Q 17/00 20060101
H01Q017/00 |
Claims
1. An electromagnetic wave testing apparatus comprising: a chamber;
an antenna shaft disposed within the chamber; a control shaft
affixed to the antenna shaft; an antenna mount, said antenna mount
movably attached to the antenna shaft; an antenna affixed to the
antenna mount; a laser pointer mounted to the antenna shaft, the
laser pointer configured and disposed to emit a laser beam onto the
antenna; and a transceiver holder, the transceiver holder
configured and disposed to be moved such that the transceiver
holder is positioned in the laser beam.
2. The apparatus of claim 1, further comprising a motor configured
and disposed to move the control shaft.
3. The apparatus of claim 2, wherein the motor is a stepper
motor.
4. The apparatus of claim 2, further comprising a position encoder
configured and disposed to indicate a rotational position of the
control shaft.
5. The apparatus of claim 4, further comprising: a processor;
non-transitory memory; wherein the processor is configured and
disposed to access the non-transitory memory, and wherein the
non-transitory memory contains instructions, that when executed by
the processor, record an encoded position of the control shaft.
6. The apparatus of claim 1, wherein the chamber is comprised of
wood.
7. The apparatus of claim 1, wherein the chamber is comprised of
plastic.
8. The apparatus of claim 1, wherein the antenna shaft is comprised
of polyoxymethylene.
9. The apparatus of claim 1, further comprising a first millimeter
wave absorber layer disposed on the inside of the chamber and a
second millimeter wave absorber layer disposed on the outside of
the chamber.
10. The apparatus of claim 9, wherein the first millimeter wave
absorber layer and the second millimeter wave absorber layer are
comprised of a material selected from the group consisting of:
urethane rubber mixed with carbon particles, epoxy resin containing
carbon particles, and polyester non-woven cloth.
11. An electromagnetic wave testing apparatus comprising: a
chamber; an antenna shaft disposed within the chamber; an antenna
mount, attached to the antenna shaft; an antenna affixed to the
antenna mount; a laser pointer mounted to the antenna shaft, the
laser pointer configured and disposed to emit a laser beam onto the
antenna; a control shaft positioned within the chamber; a
horizontal transceiver support mounted to the control shaft; and a
slidable transceiver holder slidably attached to the horizontal
transceiver support.
12. The apparatus of claim 11, further comprising a motor
configured and disposed to move the control shaft.
13. The apparatus of claim 12, wherein the motor is a stepper
motor.
14. The apparatus of claim 12, further comprising a position
encoder configured and disposed to indicate a rotational position
of the control shaft.
15. The apparatus of claim 14, further comprising: a processor;
non-transitory memory; wherein the processor is configured and
disposed to access the non-transitory memory, and wherein the
non-transitory memory contains instructions, that when executed by
the processor, establish the position of the control shaft.
16. The apparatus of claim 11, further comprising: a slot in the
chamber, wherein the control shaft is configured and disposed to
move along the slot; and a millimeter wave absorber affixed to the
control shaft.
17. A method of configuring an electromagnetic wave testing
chamber, comprising: aligning a laser pointer and an antenna,
wherein the laser pointer and the antenna are mounted on opposite
ends of an antenna shaft; orienting the antenna shaft to a
transceiver alignment position; aligning the laser pointer and the
a transceiver under test; and orienting the antenna shaft to a test
position, such that the antenna is aligned to the transceiver under
test.
18. The method of claim 17, wherein orienting the antenna shaft to
a transceiver alignment position comprises: activating a stepper
motor which is configured an disposed to move the antenna shaft to
the transceiver alignment position.
19. The method of claim 18, wherein orienting the antenna shaft to
a test position comprises: activating the stepper motor to move the
antenna shaft to the test position.
20. The method of claim 19, further comprising: recording the
position of the antenna shaft at the transceiver alignment
position; and computing the test position as 180 degrees from the
transceiver alignment position.
Description
FIELD OF THE INVENTION
[0001] The present invention relates broadly to radio frequency
measurement instrumentation, and in particular, to a radiation
signal measurement system for millimeter wave transceivers.
BACKGROUND OF THE INVENTION
[0002] In recent years an increased interest in millimeter-wave
systems has developed. As component technology matures, significant
efforts are being made to exploit the advantages that this spectral
range offers. As millimeter systems evolve, it is desirable to have
improved instrumentation and measurement techniques for system
evaluation.
SUMMARY OF THE INVENTION
[0003] In one embodiment of the present invention, an
electromagnetic wave testing apparatus is provided, comprising a
chamber, an antenna shaft disposed within the chamber, a control
shaft affixed to the antenna shaft, an antenna mount, the antenna
mount movably attached to the antenna shaft, an antenna affixed to
the antenna mount, a laser pointer mounted to the antenna shaft,
the laser pointer configured and disposed to emit a laser beam onto
the antenna, and a transceiver holder, the transceiver holder
configured and disposed to be moved such that the transceiver
holder is positioned in the laser beam.
[0004] In another embodiment of the present invention, an
electromagnetic wave testing apparatus is provided, comprising a
chamber, an antenna shaft disposed within the chamber, an antenna
mount, attached to the antenna shaft, an antenna affixed to the
antenna mount, a laser pointer mounted to the antenna shaft, the
laser pointer configured and disposed to emit a laser beam onto the
antenna, a control shaft positioned within the chamber, a
horizontal transceiver support mounted to the control shaft, and a
slidable transceiver holder slidably attached to the horizontal
transceiver support.
[0005] In another embodiment of the present invention, a method of
configuring an electromagnetic wave testing chamber is provided,
comprising aligning a laser pointer and an antenna, wherein the
laser pointer and the antenna are mounted on opposite ends of an
antenna shaft, orienting the antenna shaft to a transceiver
alignment position, aligning the laser pointer and the a
transceiver under test, orienting the antenna shaft to a test
position, such that the antenna is aligned to the transceiver under
test.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The structure, operation, and advantages of the present
invention will become further apparent upon consideration of the
following description taken in conjunction with the accompanying
figures (FIGs.). The figures are intended to be illustrative, not
limiting.
[0007] Certain elements in some of the figures may be omitted, or
illustrated not-to-scale, for illustrative clarity. In some cases,
in particular pertaining to signals, a signal name may be oriented
very close to a signal line without a lead line to refer to a
particular signal, for illustrative clarity.
[0008] Similar elements may be referred to by similar numbers in
various figures (FIGs) of the drawing, in which case typically the
last two significant digits may be the same, the most significant
digit being the number of the drawing figure (FIG). Furthermore,
for clarity, some reference numbers may be omitted in certain
drawings.
[0009] FIG. 1 shows a side view of a first embodiment of the
present invention in an antenna alignment configuration.
[0010] FIG. 2 shows a side view of a first embodiment of the
present invention in a transceiver alignment configuration.
[0011] FIG. 3 shows a side view of a first embodiment of the
present invention in a test configuration.
[0012] FIG. 4 shows a side view of a second embodiment of the
present invention in an antenna alignment configuration.
[0013] FIG. 5 shows a side view of a second embodiment of the
present invention in a transceiver alignment configuration.
[0014] FIG. 6 shows a side view of a second embodiment of the
present invention in a test configuration.
[0015] FIG. 7 is a rear view of a second embodiment of the present
invention.
[0016] FIG. 8 is a block diagram of a system in accordance with an
embodiment of the present invention.
[0017] FIG. 9 is a flowchart for a method in accordance with an
embodiment of the present invention.
DETAILED DESCRIPTION
[0018] Performing radiation measurements on a millimeter wave
transceiver is very challenging. One challenge is the requirement
of an environment free of reflections. Any surrounding metal
objects, even those as small as a millimeter, can cause significant
interference. Another challenge is the precision of alignment. The
size of an antenna is proportional to the wavelength of the signal
to be transmitted or received. For millimeter wave communication,
the antenna size can be on the order of millimeters, which requires
an accurate alignment between the measurement antenna and the
antenna under test. Without such alignment, a large measurement
error can occur. Embodiments of the present invention provide a
system and method with reduced reflections and interference and
improved alignment, to address these challenges.
[0019] FIG. 1 shows a side view of an electromagnetic wave testing
system 100 in accordance with an embodiment of the present
invention in an antenna alignment configuration. System 100
comprises chamber surface 102. Chamber surface 102 is preferably
fabricated from non-metal material such as plastic, fiberglass, or
wood. The interior side of chamber surface 102 is lined with
millimeter wave absorber material 104. The outside of chamber
surface 102 is lined with millimeter wave absorber material 106.
The material used for the inside millimeter wave absorber material
104 and the outside millimeter wave absorber material 106 may be
the same material or they may be two different materials. In one
embodiment, the inside/outside millimeter wave absorber material is
comprised of titanium dioxide and epoxy resin containing carbon
particles. In another embodiment, the inside/outside millimeter
wave absorber material is comprised of epoxy-modified urethane
rubber mixed with carbon particles. In another embodiment, the
inside/outside millimeter wave absorber material is comprised of
polyester non-woven cloth. The non-metal chamber, lined on both
sides with millimeter wave absorber material, serves to reduce
internal reflections and unwanted interference from outside sources
that could adversely affect measurements within the system 100.
[0020] An antenna shaft 108 is disposed within the chamber 103. At
one end of the antenna shaft 108 is an antenna mount 114. An
antenna 112 is affixed to antenna mount 114. At the opposite end of
antenna shaft 108 is laser mount 130. A laser pointer 128 is
affixed to laser mount 130. Laser pointer 128 comprises a laser and
associated optics for emitting a focused beam of visible light. An
electronics cable 134 contains a plurality of electrical conduits
for powering, signaling, and controlling antenna 112 and laser
pointer 128. Electronics cable 134 is routed to the outside of the
chamber to exterior electronics cable 132, which may be connected
to external power supplies, signal sources, amplifier and
controllers (not shown).
[0021] The antenna shaft 108 is affixed to a control shaft 110. The
control shaft 110 is mechanically coupled to a motor 116. A
position encoder 117 may optionally be used to more precisely
establish the angular (rotational) position of the control shaft.
In one embodiment, position encoder 117 is a rotational position
encoder configured and disposed to indicate a rotational, or
angular position of the control shaft. During use, the motor 116 is
activated to move the control shaft, hence moving the antenna shaft
to different positions during setup and testing phases.
[0022] A transceiver support post 118 is mounted to the base of the
chamber surface 102. Affixed to the transceiver support post 118 is
horizontal transceiver support 120. A slidable transceiver holder
122 is slidably mounted to the horizontal transceiver support 120.
A transceiver under test 124 is mounted to the transceiver holder
122 during use.
[0023] It is desirable to limit the use of metal within the chamber
103 to avoid undesired reflections during test. Antenna shaft 108
and transceiver support post 118 may be comprised of a rigid,
non-metal material, such as polyoxymethylene (i.e. "DELRIN"
manufactured by DuPONT of Wilmington, Del.).
[0024] As shown in FIG. 1, system 100 is in an antenna alignment
configuration. The transceiver 124 is positioned such that it is
not in the path of laser beam 126 emitted from laser pointer 128.
The laser beam 126 is aligned to the center of antenna 112. The
aligning comprises emitting laser beam 126 from laser pointer 128
onto the center of antenna 112. The alignment may be confirmed by
visual inspection by an operator. The laser pointer 128 and antenna
112 may be fine-adjusted on laser mount 130 and antenna mount 114,
respectively. This step ensures that the laser pointer 128 is
aligned with the antenna 112.
[0025] FIG. 2 shows a side view of system 100 in accordance with an
embodiment of the present invention in a transceiver alignment
configuration. In order to place system 100 into the transceiver
alignment configuration, the motor 116 is operated to rotate the
antenna shaft 108 to a position that is 180 degrees from the
antenna alignment configuration shown in FIG. 1. In one embodiment,
motor 116 is a stepper motor. The stepper motor may be used to
precisely identify the 180 degree position for the transceiver
alignment configuration. A positional encoder 117 may also be used
to achieve additional positional accuracy. The transceiver 124 is
positioned to be in the path of laser pointer 128, and the
transceiver 124 is positioned such that laser beam 142 is applied
to the center of the antenna (or other desired location) of
transceiver 124. The laser beam position may be confirmed by visual
inspection by an operator.
[0026] FIG. 3 shows a side view of system 100 in accordance with an
embodiment of the present invention in a test configuration. The
motor 116 is activated to return the antenna shaft 108 to a
position that is 180 degrees from the transceiver alignment
configuration of FIG. 2. The antenna 112 is now aligned with a
corresponding antenna on transceiver 124. The antenna 112 then may
be configured to emit electromagnetic waves 144 to test the
transceiver 124.
[0027] FIG. 4 shows a side view of a system 200 in accordance with
a second embodiment of the present invention in an antenna
alignment configuration. In this embodiment, the antenna shaft 208
is disposed within chamber 203 and affixed to the chamber surface
202 via antenna shaft mount 209. A rigid waveguide 237 supplies
electromagnetic energy input to antenna 212. Therefore, in this
embodiment, instead of rotating the antenna shaft as in the
embodiment of system 100 (FIGS. 1-3), the antenna shaft 208 of
system 200 is fixed in position. Instead, the control shaft 210
rotates to change orientation of the transceiver 224. Control shaft
210 is mechanically coupled to motor 216. Motor 216 may be a
stepper motor. A positional encoder 217 may also be used to achieve
greater positional accuracy.
[0028] A transceiver support post 218 is mounted to the outside of
the chamber surface 202 via transceiver support mounts 225 and 227.
The motor 216 and control shaft 210 are movable up and down the
transceiver support post 218 to provide vertical adjustment, which
allows varying the distance between antenna 212 and transceiver 224
during test.
[0029] System 200 comprises chamber surface 202. Chamber surface
202 is preferably fabricated from non-metal material such as
plastic, fiberglass, or wood. The interior side of chamber surface
202 is lined with millimeter wave absorber material 204. The
outside of chamber surface 202 is lined with millimeter wave
absorber material 206. The material used for the inside millimeter
wave absorber material 204 and the outside millimeter wave absorber
material 206 may be the same material or they may be two different
materials. In one embodiment, the inside/outside millimeter wave
absorber material is comprised of titanium dioxide and epoxy resin
containing carbon particles. In another embodiment, the
inside/outside millimeter wave absorber material is comprised of
epoxy-modified urethane rubber mixed with carbon particles. In
another embodiment, the inside/outside millimeter wave absorber
material is comprised of polyester non-woven cloth. The non-metal
chamber, lined on both sides with millimeter wave absorber
material, serves to reduce internal reflections and unwanted
interference from outside sources that could adversely affect
measurements within the system 200.
[0030] A millimeter wave absorber material region 243 is mounted to
the control shaft 210, parallel to the sides of the chamber surface
202. As similar millimeter wave absorber material region 241 is
mounted to the control shaft 210 opposite region 243, parallel to
the sides of the chamber surface 202. These regions serve to block
millimeter waves from entering or exiting an open slot (see FIG. 7)
in the chamber which allows for vertical movement of the control
shaft 210.
[0031] Electronics cable 232 may be connected to external power
supplies and controllers (not shown in this figure). Electronics
cable 232 provides electrical connections for laser pointer 228.
Laser pointer 228 comprises a laser and associated optics for
emitting a focused beam of visible light.
[0032] Horizontal transceiver support 220 is mounted to control
shaft 210. A slidable transceiver holder 222 is slidably mounted to
the horizontal transceiver support 220. A transceiver under test
224 is mounted to the transceiver holder 222 during use. As shown
in FIG. 4, the slidable transceiver holder 222 is positioned such
that the transceiver 224 is not in laser beam 226. Laser pointer
228 emits laser beam 226 which is centered on antenna 212. The
alignment may be confirmed by visual inspection by an operator. The
laser pointer 228 and antenna 212 may be fine-adjusted on laser
mount 230 and antenna mount 214, respectively. This step ensures
that the laser pointer 228 is aligned with the antenna 212.
[0033] FIG. 5 shows a side view of system 200 in accordance with a
second embodiment of the present invention in a transceiver
alignment configuration. In order to place system 200 into the
transceiver alignment configuration, the motor 216 is operated to
rotate the control shaft 210 to a position that is 180 degrees from
the antenna alignment configuration shown in FIG. 4. Hence, the
transceiver 224 is now facing the laser pointer 228.
[0034] In one embodiment, motor 216 is a stepper motor. The stepper
motor may be used to precisely identify the 180 degree position for
the transceiver alignment configuration. A positional encoder 217
may also be used to achieve additional positional accuracy. The
transceiver 224 is positioned to be in the path of laser pointer
228 by sliding transceiver holder 222 into an extended position,
such that laser beam 242 is positioned on the center of a
corresponding antenna (or other desired location) of transceiver
224. The laser beam position may be confirmed by visual inspection
by an operator.
[0035] FIG. 6 shows a side view of system 200 in accordance with a
second embodiment of the present invention in a test configuration.
The motor 216 is activated to return the control shaft 210 to a
position that is 180 degrees from the transceiver alignment
configuration of FIG. 5. The antenna 212 is now aligned with the
transceiver 224. The antenna 212 then may be configured to emit
electromagnetic waves 244 to test the transceiver 224.
[0036] FIG. 7 is a rear view of system 200. In this view, open slot
248 is shown. The control shaft (210 of FIG. 6) extends from the
motor 216, through the open slot 248, and into the chamber of
system 200. The motor 216, and control shaft 210 may be moved along
the transceiver support post 218 to provide a vertical adjustment,
which controls the distance between antenna 212 and transceiver 224
during test. Additional millimeter wave absorber regions (see 241
and 243 of FIG. 4) serve to prevent ingress or escape of
electromagnetic radiation through open slot 248.
[0037] FIG. 8 is a block diagram of a system 800 in accordance with
an embodiment of the present invention. System 800 comprises a main
controller 818. Main controller 818 may be a computer comprising
memory 820, and a processor 822 which is configured to read and
write memory 820. The memory 820 may be non-transitory memory, such
as flash, ROM, non-volatile static ram, or the like. The memory 820
contains instructions that, when executed by processor 822, control
the various subsystems to operate system 800. Main controller 818
may also comprise a display 824 and a user interface 826 for
interacting with the system 800. The user interface 826 may
comprise a keyboard, touch screen, mouse, or the like.
[0038] The main controller 818 may send data to and receive data
from millimeter wave test apparatus 810. Millimeter wave test
apparatus 810 may be a movable antenna shaft embodiment as shown in
FIGS. 1-3, or may be a fixed antenna shaft embodiment as shown in
FIGS. 4-7. The processor 822 may access instructions stored in
memory 820 and execute the instructions in order to control the
motor (116 or 216 in FIGS. 1-7) to move the antenna or transceiver
into the desired orientation for alignment or test. In some
embodiments, the motor is a stepper motor, and the processor moves
the stepper motor a predetermined number of steps to achieve a 180
degree position change between the transceiver alignment position
(laser faces transceiver) and the transceiver testing position
(antenna faces transceiver). The main controller 818 may read
positional data from one or more encoders (117 or 217 in FIGS. 1-7)
from the millimeter wave test apparatus 810 to more precisely
determine the transceiver alignment position (laser faces
transceiver) and the transceiver testing position (antenna faces
transceiver). The processor 822 may also control activation and
deactivation of the laser (128 or 228 in FIGS. 1-7). The processor
822 may execute instructions stored in memory 820 that record the
position of the antenna shaft at the transceiver alignment
position, and then compute the test position as 180 degrees from
the transceiver alignment position.
[0039] FIG. 9 is a flowchart 900 for a method in accordance with an
embodiment of the present invention. In process step 950, the
antenna and laser are aligned (see FIG. 1 and FIG. 4). In process
step 952, the transceiver is moved into an alignment position. In
process step 954, the transceiver and laser are aligned (see FIG. 2
and FIG. 5). In process step 956, the transceiver is moved into a
test position (see FIG. 3 and FIG. 6). The transceiver can then be
tested by emitting electromagnetic waves from the antenna (see 144
of FIGS. 3 and 244 of FIG. 6).
[0040] As can now be appreciated, embodiments of the present
invention provide an improved radiation signal measurement system
for millimeter wave transceivers. Embodiments of the present
invention utilize a laser to align the laser with an antenna. The
transceiver is then moved into the path of the laser to align the
laser with the transceiver. The transceiver or antenna orientation
is changed such that the transceiver and antenna face each other,
in an aligned position. Millimeter wave absorber material is
applied to the inside and outside of the testing chamber to
minimize reflections and interference from outside sources.
[0041] Although the invention has been shown and described with
respect to a certain preferred embodiment or embodiments, certain
equivalent alterations and modifications will occur to others
skilled in the art upon the reading and understanding of this
specification and the annexed drawings. In particular regard to the
various functions performed by the above described components
(assemblies, devices, circuits, etc.) the terms (including a
reference to a "means") used to describe such components are
intended to correspond, unless otherwise indicated, to any
component which performs the specified function of the described
component (i.e., that is functionally equivalent), even though not
structurally equivalent to the disclosed structure which performs
the function in the herein illustrated exemplary embodiments of the
invention. In addition, while a particular feature of the invention
may have been disclosed with respect to only one of several
embodiments, such feature may be combined with one or more features
of the other embodiments as may be desired and advantageous for any
given or particular application.
* * * * *